Inexpensive power supply

[daeg]

can you get by with just one transformer, but an individual secondary (and rectifier, filter, regulator) for each output?

I’ve seen diy projects both ways, just wondering if there is actually a difference.

That's a good question. I'd think you'd need a transformer with multiple secondaries, rather than multiple taps, for ground isolation. That's probably how the pro / truly isolated units are designed.

Like this: